Flow-Induced Vibration in a Single Row of Cylinders With p/D = 1.26

Abstract

Abstract Crossflow over a row of cylinders with a close space ratio presents an asymmetric configuration with large and narrow wakes behind the cylinders. The wake interaction can impact the vibration response of the cylinders. In tube banks, the impact results in damages to the equipment. The present experimental study aims to analyze the influence of close space observed in a single row of cylinders on the flow-induced vibration. The study compares a single row with fixed cylinders and a single row with one cylinder free to vibrate. The cylinder free to vibrate is tested in four configurations. The study was conducted with an aerodynamic channel with a cross-section of 0.193 × 0.146 m and smooth cylinders with a diameter of 25.1 mm, space ratio is 1.26. The measurements are executed with hot-wire anemometry and accelerometers, for the cases with one cylinder free to vibrate and with hot-wire anemometry and microphones for the case with all fixed cylinders. The Reynolds number ranges between 1.0 × 104 and 4.5 × 104, obtained with the reference flow velocity, measured with a Pitot tube, and the cylinder diameter. The comparison between the wake response for single row fixed and single row and free to vibrate are executed using Fourier transform and Wavelet Transform. The comparison of the results with the models presented in the literature to predict the elastic instability of the fluid in a single row of cylinders is performed.